1. Field of the Invention
The present invention relates to a technique for supporting the utilization of a library storing three-dimensional models of components in a three-dimensional computer aided design (3D-CAD) system.
2. Description of the Related Art
Along with the advancement of computer technologies, the designs of various apparatuses using the 3D-CAD system have become a common practice in recent years. The improvement of efficiency in designing using a 3D-CAD system is being aimed at by pre-storing in a library the 3D models of common components such as screws for use in various kinds of apparatuses and by utilizing the library. In the conventional system, however, a supporting system for a user to utilize such a library effectively has not been adequately developed. This necessitates the user to endure cumbersome manual works in some processes of design.
Such conventional 3D-CAD system and library are described by referring to FIGS. 1 through 3. Note that a 3D model is simply noted as “model” in the following description. FIG. 1 exemplifies the configuration of a conventional system including a 3D-CAD system and a library.
Referring to FIG. 1, the library 1001 stores and manages the models of common components such as screws, bolts, nuts, rivets and such. The components whose models are stored in the library are those necessary for designing apparatuses using the 3D-CAD system 1002 or those highly frequently used. A specific example is, one file is constituted by the data of the model of one component, a drawing number which is the number assigned to the drawing representing an individual model is used for the file name of each model, and such plural files are registered and held in the library 1001.
Users of the system shown in FIG. 1 are the design engineers of various apparatuses. A user designs an apparatus by using the 3D-CAD system 1002.
The 3D-CAD system 1002 comprises a model data load unit 1003 for loading the data of the model of a component onto the 3D-CAD system 1002 from the library 1001 and a model placement unit 1004 placing the loaded model of the component designated by the user to the user designated position.
When carrying out a design, the user selects the model of a required component and makes the model data load unit 1003 load the selected model. The user designates, to the model placement unit 1004, an appropriate position in the model of the apparatus to be designed as the position in which the loaded model of the component is to be placed. In compliance to the designation, the model placement unit 1004 moves the loaded model to the designated position, rotates the model as appropriate and places it in the position. Such a use of the library 1001 frees an individual designer from a need to design the common components such as screws and thereby a higher efficiency of the design work is realized.
Meanwhile, since a very large number of models are stored in the library 1001, it is sometimes difficult for a user to find the model of a component desired by the user from the library 1001 or to manage the data stored therein. Accordingly used is a data management tool 1005 for assisting the user.
The data management tool 1005 is a tool similar to a common file search tool. An individual model is generally included in the library 1001 in the form of a file using the drawing number as the file name. Accordingly, the user pre-investigates the drawing number of the required component by referring to a catalog and/or a specification sheet and inputs the drawing number to the data management tool 1005, thereby being able to search and obtain the model of the required component. Further, a registrar who has registered the model file in the library 1001, a creation date when the model file has been created, etc., in addition to the file name, can generally be utilized as a search condition for the data management tool 1005.
Referring to FIG. 1, the pairs of arrows connecting the library 1001 and model data load unit 1003 indicate that the information specifying a model is provided from the model data load unit 1003 to the library 1001 and that the data of the specified model is sent from the library 1001 to the model data load unit 1003. Further, when the user utilizes the data management tool 1005, a model is specified and loaded by way of the data management tool 1005. This procedure is indicated by the arrows connecting the library 1001 and the data management tool 1005 and the arrows connecting the data management tool 1005 and the model data load unit 1003. In contrast, the operations of loading and placing are mutually independent and therefore no arrow exists to connect the model data load unit 1003 to the model placement unit 1004.
FIG. 2 is the flow chart showing the flow of the process for placing one component in a design utilizing the system shown in FIG. 1. The design process of an individual apparatus and such includes the process for placing models of components in the model of a design target. FIG. 2 is the flow chart of the process related to such a placement of one component.
In the step S1001 (also abbreviated as “S1001” hereinafter), the user determines the model of a component to be loaded. As described above, a model is managed by the file name using the drawing number. The user accordingly determines the specification of the required component, investigates the drawing number of a specific component satisfying the determined specification by using a catalog, a specification document and such, and determines the drawing number.
In S1002, the user then searches for the model as the loading subject determined in the S1001 by using the data management tool 1005. If there is the model specified by the user in the library 1001, the model of the loading subject is selected as a result of the search.
The selected model is loaded onto the 3D-CAD system 1002 by the model data load unit 1003 in the following S1003.
In the subsequent S1004, the user designates both the position and direction, in which the model is to be placed, and the loaded model, so that the model placement unit 1004 reflects the model of the component to the model of the design target in accordance with the user's designation. That is, the model placement unit 1004 moves the model of the component to a position designated in the model of the design target, rotates the model as appropriate and places the model of the component in the position.
FIG. 3 is a diagram schematically illustrating the process of FIG. 2. FIG. 3 shows that the model of a screw 1006 is loaded onto the 3D-CAD system 1002 from the library 1001 and that the model of the screw 1006 is placed in a screw hole (more precisely, the model thereof) for fastening plates 1007 and 1008 together.
The conventional system as described by referring to FIGS. 1 through 3 bears the problems as follows.
A first problem is that the S1001 of FIG. 2 takes the user effort to investigate a drawing number. In many cases, the model of a component is registered in the library 1001 by using the file name utilizing the drawing number of the aforementioned model as exemplified above.
Therefore, the user needs to determine a specific drawing number on the basis of the specification of the required component. In the current situation, the user performs an investigation for determining a drawing number by referring to a catalog, a specification sheet or the like. The investigation is not automated and therefore is time consuming.
A second problem is that it also takes an effort to search a model corresponding to the determined drawing number from the library 1001. It takes the user efforts to find a target model from the library 1001 if it stores a very large number of models. Even if the models are hierarchically grouped, it takes the user to trace along a deep hierarchical layer to find the target model if there is a large number of models.
Meanwhile, in order to reduce the amount of effort, the user may search it by using a file name as key by using the data management tool 1005, which requires the user to operate simultaneously two applications alternately, that is, the 3D-CAD system 1002 and data management tool 1005, undermining a work efficiency.
Techniques related to the above described problems include the following.
A design assisting device for printed wiring board noted in reference patent document 1 comprises a part library storing the manufacture conditions such as the applicability of a water cleaning and a manufacture condition library storing conditions, which are represented by the combinations of the manufacture conditions and/or the arrangement information of parts, and the validity of manufacturing characteristics by correlating between the conditions and the validity.
When a designer specifies a required function, a part(s) possessing the function is/are searched from the part library. The designer selects a part to be used from among the searched part(s). Upon selecting all the required parts, the designer determines the arrangement positions of the respective parts on the printed wiring board. Then, the design assisting device for printed wiring board compares the manufacture conditions and the determined arrangement positions of the selected parts with the contents of manufacture condition library, thereby judging the producibility (i.e., the validity of manufacturing characteristics) of each part. This configuration enables a designer without the assembly know-how to examine the producibility and modify the design if required.
A component selection support system noted in reference patent document 2 is configured in advance so that components possessing the same functional characteristics are classified into a group, a group code is assigned to the group, parameters such as the price and life of each component are registered in a library, and the search conditions represented by the sort conditions of the parameters are determined.
When performing a design, the group code is designated by the designer and a most optimal component is automatically searched and selected from among the group on the basis of the search condition. This configuration makes it possible to select the most appropriate component without depending on the experience of a designer.    Patent document 1: Laid-Open Japanese Patent Application Publication No. 2001-196720    Patent document 2: Laid-Open Japanese Patent Application Publication No. 2006-59006
The inventions respectively noted in the reference patent documents 1 and 2 are in common in terms of sorting a plurality of components into one group in accordance with the function. Such a grouping, however, is not sufficient for solving the problems described above. The reason is that the number of such groups may be sometimes so enormous that finding and designating a desired group from among the enormous number of groups causes a user as many manual operations as those caused when finding and designating a desired component from among an enormous number of components.
There are various kinds of components including mechanical components such as screws, bolts and nuts in addition to the electronic circuit components exemplified in the reference documents 1 and 2. Grouping together, into a single group, a plurality of kinds of components which satisfy a specification representing the same function and which are mutually interchangeable is not always appropriate for mechanical components.
For example, although two screws with different size are the same in terms of a common function of fastening two members together, they are not interchangeable in a situation in which a screw hole of a specific size is already determined. There is accordingly the case of mechanical components in different sizes to be regarded as corresponding to different functions and therefore they are to be categorized into different groups.
Meanwhile, there are diverse sizes of mechanical components. Moreover, the size of one mechanical component is seldom represented by a single value, and instead represented by a combination of respective sizes of a plurality of parts of a component. There are a large number of such combinations in a certain mechanical component. Therefore, grouping a mechanical component by size increases the number of groups enormously.
It is cumbersome for the user to find a desired group from among such an enormous number of groups. Therefore the method of grouping components by function is insufficient to solve the problems described above.